We conducted an English-language search of databases, including PubMed, EMBASE, Web of Science, and Google Scholar, by using the terms “Chronic fatigue syndrome” OR “myalgic encephalomyelitis” AND “cytokine” OR “Tumor necrosis factor-α” OR “Interferons” OR “Interleukins” OR “TGF-β”. The gene discussed is TNF; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.